Good evening. my right gland behind my ear is swollen and sore. should i be worried?

Suggests infection: in ear or scalp. Apply warm compress to see if it becomes less sore. Otherwise, don't mash or mess with it. If you have ear pain or drainage, need to be seen.

That could be: a cyst, an enlarged lymph node or a infection. Red, hot with pus - seek med eval.

Lymph node.: That sounds like enlargement of a postauricular lymph node, which can happen when you're sick with a sinus infection or ear infection . As long as the lymph node goes away in 2-4 weeks, then should be fine. If it doesn’t then have doctor evaluate.